14 January 2009

Plan B: Green green shore of Pasir Ris

A green welcome carpet of Sea lettuce (Ulva sp.) blanketed the sandy shores of Pasir Ris!Under the seaweeds were the perennial meadows of Spoon seagrasses (Halophila ovalis). This explosion of seaweeds is great for marine life as it provides food and shelter for small animals which in turn are eaten by larger ones.

Many are well camouflaged, like this little green prawn (Family Penaeidae) that will grow up to be the kind that we eat. There were also lots of tiny Flower crabs (Portunus pelagicus). So seagrasses and seaweeds are vital if we want to enjoy fishing and a continuing supply of seafood. We can't take this for granted. Recently there was a report that fish and prawn catches in Malaysia were severely threatened by coastal habitat losses.
Some animals look just like seaweeds! Kok Sheng found this Hairy sea hare (Bursatella leachii) which is a first sighting for me on Pasir Ris! It's the kind with more orangey 'hair' which I don't see very often. Later on, we found another slug that looked like the Hairy sea hare, but it didn't move much. November wisely pointed out that it might be already dead.
Kok Sheng spotted this See-through sea cucumber (Paracaudina australis) that we seldom see, and usually only on Chek Jawa and Changi. It has really short stubby feeding tentacles, and it's so transparent you can sometimes see its innards! Kok Sheng is an echinoderm magnet and whenever he is around, we get to see all kinds of strange and wondrous echinoderms.There were wriggly small brittlestars among the seaweeds.A small sea star that might be a young Cake sea star (Anthenea aspera). It's hard to tell when they are so tiny.
And of course, lots and lots and LOTS of Sand stars (Astropecten sp.) that Kok Sheng is currently studying. He was very glad to see them.
These little branching things were growing on some parts of the seaweeds. I have no idea what they are. I don't even know whether they are plants or animals! Regardless of which, I'm sure they are part of the food chain that results in seafood and fishes for us!

Pasir Ris means 'narrow sandy beach' so there's large stretches of sandy areas which are not covered in green stuff. The worms are more obvious here without the cover of seaweeds or seagrasses.I don't know what kind of worm this is. It's probably NOT a bristleworm is all that I know.This one is a broad and bristley bristleworm!
Many britlesworms live in tubes and are called tubeworms. You will seldom see a tubeworm worm outside its tube. This pair of tubes was surrounded by a collection of odd little things. I don't know what they might be. Eggs? Poop?
These very very VERY long worms are ribbon worms (Phylum Nemertea). They are unsegmented predatory worms that eat other animals. If you take a closer look at them, they are quite pretty with handsome stripes. I don't even know whether these are two worms or one very long worm!Flatworms (Phylum Platyhelminthes) are another kind of worm altogether. I have no idea of the identity of this flatworm, but often see it in numbers in silty sandy places, so I call it the Silt flatworm. This flatworm has a pair of tiny pointy tentacles in the middle of the 'head' instead of just pseudo-tentacles made up of the front margin of the body.Worms make great meals! I didn't even notice the little Sentinel crab (Macrophthalmus sp.) chomping on this pink bristleworm.Well camouflaged in sandy pools are lots of small gobies. I don't know the identity of these fishes but they are really pretty if you take a closer look at them.Clusters of little snails on the sand often turn out to be inhabited by little hermit crabs. Some of them had sea anemones on their shells.
On the rocky areas are small clumps of sponges. Including this prickly orange ball sponge. Well, I think it's a sponge. Do let me know if this is entirely wrong.
We came across many of these elegantly sculptured shells. Alas, they were all empty. They seem to have floated in from deeper waters. From Tan, K. S. & L. M. Chou, "A Guide to the Common Seashells of Singapore", this might be Phalium glaucum of the Family Cassidae (Helmet shell snails). According to the Guide, these snails are 8-9cm. They are carnivorous and live in sand, feeding mainly on sea urchins. The Family Cassidae also includes the helmet shell snails that feed on the Crown-of-thorns sea stars!

We're not sure why there are so many empty shells of this snail. The shells were very clean so they are probably recently 'vacated'. Well, the hermit crabs I'm sure will put them to good use.

Near the mouth of a freshwater outflow, there were firm 'pillows' of sand and silt with tiny holes in them.Kok Sheng is very happy to see them as these are Nest mussels (Muscilita senhausii). These minute mussels create a nest of threads that they secrete. These bind the sand into hillocks and pillows. Each slit is a tiny mussel. Among the animals that eat these mussels are the Sand stars that Kok Sheng is studying.This, unfortunately, is just a plastic pillow. Being next to a major park that is well used by the public, there is a great deal of trash on the shore. Mostly food packaging: snacks, instant noodles, and packet drinks. It's sad to see this living shore impacted by careless and thoughtless people.

Plan A was to visit a shore where we had earlier found many special animals.Unfortunately, it appears to have already been lost to development. The trees and vegetation around the shore have been cleared, containers installed and large mounds of sand piled nearby. Heavy equipment surrounded the area on land and sea. Access to the area was severely limited. It was with a very heavy heart that we decided to abandon the trip and go to Pasir Ris instead.

We never know when a shore will be lost.

This is why we need to appreciate our shores while we still have them.